1. Field of the Invention
The present invention relates to an audio signal interpolation method and an audio signal interpolation apparatus for performing interpolation to compensate for an audio signal lost due to the occurrence of an error or the like.
2. Description of the Related Art
Interpolation techniques for processing of audio signals including acoustic signals and speech signals are widely used for signal processing such as codec processing, synthesis processing, or error correction processing, and signal transmission processing.
Known speech synthesis or audio signal interpolation is performed in two stages, that is, an analysis stage and a formation stage (see, for example, Audio Extrapolation—Theory and Applications). First, in the analysis stage, signals preceding and/or following an interpolation segment are analyzed. This analysis includes assumption of a pitch period, classification of signals into periodic signals and noise signals performed to determine whether a signal has periodicity, and power computation. Next, in the formation stage, a signal for the interpolation segment is formed by performing extrapolation using pitch periods of the signals preceding and/or following the interpolation segment, and then power of the formed signal is controlled.